11. If you believe humans have free will, why would humans have free will if God exists? Why are we able to exercise free will in some situations but not others?
I don't believe humans have free will. The Bible says, and observation and personal experiences bears it out, that people are enslaved to sin. We are not free willed because we can't choose not be under the guilt of sin. Our guilt is deserved because everyone of us sins - either voluntarily or involuntarily. The first question doesn't make sense from this point of view and besides why make God's existence contingent on our free will? It doesn't. The second question actually supposes that we don't have free will (as much of philosophy expresses it "libertarian free will"). If we had that kind of free will I would expect that we would be able to do anything we want in any situation and we cannot. I'm not saying that humans have no will of our own - we do and it is enslaved to sin. The Gospel is that Jesus came to free us and you can be freed and finally see and think clearly. This is what Jesus taught and what the Apostles taught. How does God's sovereignty and our will interact? That depends on what God decides. Sometimes God supersedes that and changes us so that we don't even realized that we would have willed something else - that is definitely the case whenever anyone of us does something "good". And sometimes God makes it plain God is doing something outside of our own will be allowing us to see things transpire contrary to our desires.
The Secular Outpost: 20+ Questions for Theists
